Process of producing carbon monoxide from light hydrocarbons

Abstract

Carbon monoxide is produced from light hydrocarbons having an average C number not greater than 15 by catalytic cracking with water vapor in two cracking stages followed by separation of the carbon monoxide from the product gas employing the following steps:

What is claimed is: 
     
       1. Process for producing carbon monoxide from light hydrocarbon feedstock having an average C number not greater than 15 and containing sulfur impurities which comprises: a. mixing the hydrocarbon feedstock with 0.02 - 0.1 standard cubic meter hydrogen per kilogram of hydrocarbon feedstock;   b. subjecting this mixture to desulfurization;   c. mixing the desulfurized mixture with superheated process steam in a ratio of 1.1 - 1.7 moles per mole of carbon in the feedstock;   d. reacting the resulting mixture from (c) in contact with a catalyst containing 35 - 70 percent by weight of nickel in a reaction zone at temperatures of 300° - 500° C and at a pressure of 10 - 20 kilograms per square centimeter to produce a high methane rich gas;   e. reducing the pressure of said rich gas by an amount of 4 - 12 kilograms per square centimeter and reacting said rich gas in a tubular heating zone in contact with an indirectly heated catalyst containing 10 - 30 percent by weight of nickel at a temperature in the range of 850° - 980° C to produce a product gas which is rich in carbon monoxide and hydrogen;   f. cooling said product gas and removing carbon dioxide and water vapor therefrom; and   g. separating carbon monoxide from said cooled product gas by condensation of carbon monoxide.   
     
     
       2. Process of claim 1 wherein hydrogen from step (g) is recycled and mixed with the hydrocarbon feedstock in step (a). 
     
     
       3. Process of claim 1 wherein the weight ratio of steam to hydrocarbon feedstock in step (c) is between 2.1:1 and 1.8:1. 
     
     
       4. Process of claim 1 wherein carbon monoxide is separated in step (g) by being scrubbed with liquid methane. 
     
     
       5. Process of claim 1 wherein the catalyst used in step (d) is on a magnesium silicate or magnesium spinel support.